Monday, 4 June 2012

A quarter of a pint of beer a day?

My take on the media reporting of our recent paper on alcohol and health

Our paper modelling the costs and benefits to health of
alcohol consumption in England came out last week. It was widely covered by the media including
the News Quiz on Radio 4 where the panellists had a good laugh at the findings
of the research. Our paper shows that
the optimum average consumption level for drinkers in this country is about 5g/day
(about half a unit) and this would avert or delay about 4600 deaths per year. I should
emphasise that this paper describes what is and makes some tentative
conclusions about what should be the case.
There has been little criticism of the methods for, and results of, the
paper but much derision at the supposed conclusions.

There is a line in the paper that reads: “On this basis, we recommend that the public
health target for alcohol consumption in England should be to reduce median
alcohol consumption to half a unit per day for both men and women.” We
should, perhaps, have been clearer about what we meant by ‘a public health
target’. We meant a target level for
the whole population of England and NOT a target for any one individual. By median intake we meant the average for everyone
not the individual’s average intake.

The paper got reported in the press with such headlines as ‘Cut
alcohol intake to just a quarter pint of beer a day, experts advise’ (Guardian)
and ‘Don't drink more than quarter of a pint a DAY’ (Daily Mail). It might sound quibbling but we weren’t advising
people to drink just quarter of a pint a day.
What we were trying to say was that if people ON AVERAGE drank quarter of
a pint a day the whole population would be healthier. And if the Government was to advise people
about their drinking then they should tell them the truth i.e. that alcohol is
good for them in small amounts but that anything over quarter a pint is (on
average) harmful.

The Guardian and Mail clearly failed to understand what we
were getting at but some other newspapers did seem to understand. For example the Telegraph’s headline was ‘ Sticking
to a quarter pint of beer a day would save thousands of lives’ and BBC Online’s headline was ‘Reducing
alcohol to half a unit a day saves lives’.
These headlines –if somewhat imprecise - better capture what our paper says
and both wisely avoid the issue of what the public should be advised on the
basis of our research.

Why did the Guardian claim that we – the expert authors of
the paper - were advising people to drink just a quarter a pint of beer a day? We didn’t speak to the journalist in
question and this was just sloppy journalism.
The Telegraph article, for example, doesn’t anywhere suggest that we
were advising the public anything.

However it would be disingenuous of us to pretend that we
weren’t hoping that our research would have some effect on the public and their
view of alcohol. And we did say in the
paper that, “we recommend that the public health target for alcohol consumption
in England should be to reduce median alcohol consumption to half a unit per
day for both men and women.” Furthermore there is clearly some relationship
between what would be good for the population and what individuals should
individually drink if their health is to be optimised.

But the paper does not address the question of how our epidemiological
research should be translated into advice to the public. Perhaps we should have been clearer in that
regard. How results such as ours should
be used to inform advice to the public should be the subject of future investigation
– not necessarily by us. But there are two
things that might be said in a preliminary sort of way.

Firstly, as some commentators have pointed out, a median
intake of half a unit a day is even theoretically compatible with the
Government’s ‘recommended daily limits’ of 3-4 units a day for men and 2-3
units a day for women - for, as Andrew Sales points out in the comments on our
paper at BMJ Open ‘at this level of population consumption [an average of half
a unit a day] the model…allows for individual consumptions at much higher
level.’ (If the median is half a unit
then 50% of people can afford to drink more than a half a unit.)

Note that the Government does not says that 3-4 units for
men/2-3 units for women is optimal or even safe as, for example, the Daily Mail
describes the Government’s ‘recommended daily limit’. In fact the Government says that ‘There's no
guaranteed safe level of drinking, but if you drink less than the recommended
daily limits, the risks of harming your health are low’. Well it depends on what you mean by ‘low’. I would argue that the risk of drinking 2-4 units
is hardly ‘low’ but my ‘low’ may not be their ‘low’. Furthermore I question whether 2-4 units
should be ‘recommended’. What is to be ‘recommended’
about this ‘limit’?

Secondly it is not clear – as David Spiegelhalter has
pointed out in a rather good commentary on our paper – that what the public should
be advised is what would absolutely minimise their risk of ill health. For some other bits of public health advice the
Government doesn’t attempt to advise what would be ideal but what would be
realistic. For instance eating 5
portions of fruit and vegetables is not the best we could do. In Greece they eat around 10 portions of
fruit and vegetables (on average) each day and in consequence Greece’s cardiovascular
disease rates are lower than ours. The Government’s 5–a-day message was designed to
be a realistic target for individuals and the population not what we should
ideally eat. On the other hand (contra Spiegelhalter)
with other public health advice the Government does recommend to the public what
would absolutely minimise their risk.
Take smoking for instance. Here
the advice is to quit not just cut down.

So has our paper and the media coverage helped or hindered
the confusion about the effects of alcohol consumption on health and how much
we should drink. I am hoping that when
the dust has settled, its overall contribution e.g. to the Government’s currentreview of its alcohol guidelines, might be helpful. As the Commons Science and Technology
Committee says these are confusing. On a personal note I am not pleased by the
results of our research. I was hoping
that alcohol might have been better for my health.